In a mobile communication system, setting up a connection between a mobile station and a wireless access network device is started upon a connection request from the mobile station or the wireless access network device.
FIG. 1 is a sequence diagram exemplifying a sequence of setting up a connection between a mobile station and a wireless access network device when the connection request is made from the side of the mobile station.
As shown in FIG. 1, first, the mobile station transmits a radio resource control (RRC) connection request signal through a random access channel (RACH), which is mapped into (namely, associated with) a physical random access channel (PRACH) (in other words, transmitting the random access channel (RACH), which is a transport channel, with the physical random access channel (PRACH), which is a physical channel.
After receiving the RRC connection request signal, the wireless access network device transmits a RRC connection set-up signal through a forward access channel (FACH), which is mapped into a secondary common control physical channel (SCCPCH).
Next, after receiving the RRC connection setup signal, the mobile station switches to a dedicated physical channel (DPCH), and transmits a RRC connection setup complete signal. After, that, signal transmission and reception are performed with the dedicated physical channel (DPCH).
As described above, in the related art, the mobile station and the wireless access network device need to switch, before the connection setup is completed, the physical channel for signal transmission and reception from the physical random access channel (PRACH), which is an uplink common physical channel, to the secondary common control physical channel (SCCPCH), which is a downlink shared channel, and further to the dedicated physical channel (DPCH).
In addition, after the mobile station transmits the radio resource control (RRC) connection request signal, if the mobile station fails to receive the RRC connection set-up signal from the wireless access network device within a time period T300, which is designated by the wireless access network device in advance, the mobile station needs to repeatedly execute the above connection operations up to the number of times (N300) designated by the wireless access network device.
For example, this technique is disclosed in “3GPP TS 25.331 v6.5.0”.